# =============================================================================
# OWSLib. Copyright (C) 2005 Sean C. Gillies
#
# Contact email: sgillies@frii.com
#
# $Id: wfs.py 503 2006-02-01 17:09:12Z dokai $
# =============================================================================

import itertools
import logging

from owslib import util

from io import BytesIO
from urllib.parse import urlencode
from owslib.util import (
    testXMLValue,
    extract_xml_list,
    ServiceException,
    xmltag_split,
    Authentication,
    openURL,
    log,
)
from owslib.etree import etree
from owslib.fgdc import Metadata
from owslib.iso import MD_Metadata
from owslib.crs import Crs
from owslib.namespaces import Namespaces
from owslib.feature.schema import get_schema
from owslib.feature.common import (
    WFSCapabilitiesReader,
    AbstractContentMetadata,
)

LOGGER = logging.getLogger(__name__)

has_pyproj = False

try:
    import pyproj
    has_pyproj = True
except ImportError:
    LOGGER.warning('pyproj not installed')

n = Namespaces()
WFS_NAMESPACE = n.get_namespace("wfs")
OGC_NAMESPACE = n.get_namespace("ogc")


# TODO: use nspath in util.py
def nspath(path, ns=WFS_NAMESPACE):
    """
    Prefix the given path with the given namespace identifier.

    Parameters
    ----------
    path : string
        ElementTree API Compatible path expression

    ns : string
        The XML namespace. Defaults to WFS namespace.
    """
    components = []
    for component in path.split("/"):
        if component != "*":
            component = "{%s}%s" % (ns, component)
        components.append(component)
    return "/".join(components)


class WebFeatureService_1_0_0(object):
    """Abstraction for OGC Web Feature Service (WFS).

    Implements IWebFeatureService.
    """

    def __new__(
        self,
        url,
        version,
        xml,
        parse_remote_metadata=False,
        timeout=30,
        headers=None,
        username=None,
        password=None,
        auth=None,
    ):
        """ overridden __new__ method

        @type url: string
        @param url: url of WFS capabilities document
        @type xml: string
        @param xml: elementtree object
        @type parse_remote_metadata: boolean
        @param parse_remote_metadata: whether to fully process MetadataURL elements
        @param headers: HTTP headers to send with requests
        @param timeout: time (in seconds) after which requests should timeout
        @param username: service authentication username
        @param password: service authentication password
        @param auth: instance of owslib.util.Authentication
        @return: initialized WebFeatureService_1_0_0 object
        """
        obj = object.__new__(self)
        obj.__init__(
            url,
            version,
            xml,
            parse_remote_metadata,
            timeout,
            headers=headers,
            username=username,
            password=password,
            auth=auth,
        )
        return obj

    def __getitem__(self, name):
        """ check contents dictionary to allow dict like access to service layers"""
        if name in list(self.__getattribute__("contents").keys()):
            return self.__getattribute__("contents")[name]
        else:
            raise KeyError("No content named %s" % name)

    def __init__(
        self,
        url,
        version,
        xml=None,
        parse_remote_metadata=False,
        timeout=30,
        headers=None,
        username=None,
        password=None,
        auth=None,
    ):
        """Initialize."""
        if auth:
            if username:
                auth.username = username
            if password:
                auth.password = password
        self.url = url
        self.version = version
        self.timeout = timeout
        self.headers = headers
        self.auth = auth or Authentication(username, password)
        self._capabilities = None
        reader = WFSCapabilitiesReader(self.version, headers=self.headers, auth=self.auth)
        if xml:
            self._capabilities = reader.readString(xml)
        else:
            self._capabilities = reader.read(self.url, self.timeout)
        self._buildMetadata(parse_remote_metadata)

    def _buildMetadata(self, parse_remote_metadata=False):
        """set up capabilities metadata objects: """

        self.updateSequence = self._capabilities.attrib.get("updateSequence")

        # serviceIdentification metadata
        serviceelem = self._capabilities.find(nspath("Service"))
        self.identification = ServiceIdentification(serviceelem, self.version)

        # serviceProvider metadata
        self.provider = ServiceProvider(serviceelem)

        # serviceOperations metadata
        self.operations = []
        for elem in self._capabilities.find(nspath("Capability/Request"))[:]:
            self.operations.append(OperationMetadata(elem))

        # serviceContents metadata: our assumption is that services use a top-level
        # layer as a metadata organizer, nothing more.

        self.contents = {}
        featuretypelist = self._capabilities.find(nspath("FeatureTypeList"))
        features = self._capabilities.findall(nspath("FeatureTypeList/FeatureType"))
        for feature in features:
            cm = ContentMetadata(
                feature, featuretypelist, parse_remote_metadata, auth=self.auth
            )
            self.contents[cm.id] = cm

        # exceptions
        self.exceptions = [
            f.text for f in self._capabilities.findall("Capability/Exception/Format")
        ]

    def getcapabilities(self):
        """Request and return capabilities document from the WFS as a
        file-like object.
        NOTE: this is effectively redundant now"""
        reader = WFSCapabilitiesReader(self.version, auth=self.auth)
        return openURL(
            reader.capabilities_url(self.url), timeout=self.timeout,
            headers=self.headers, auth=self.auth
        )

    def items(self):
        """supports dict-like items() access"""
        items = []
        for item in self.contents:
            items.append((item, self.contents[item]))
        return items

    def getfeature(
        self,
        typename=None,
        filter=None,
        bbox=None,
        featureid=None,
        featureversion=None,
        propertyname="*",
        maxfeatures=None,
        srsname=None,
        outputFormat=None,
        method="{http://www.opengis.net/wfs}Get",
        startindex=None,
    ):
        """Request and return feature data as a file-like object.

        Parameters
        ----------
        typename : list
            List of typenames (string)
        filter : string
            XML-encoded OGC filter expression.
        bbox : tuple
            (left, bottom, right, top) in the feature type's coordinates.
        featureid : list
            List of unique feature ids (string)
        featureversion : string
            Default is most recent feature version.
        propertyname : list
            List of feature property names. '*' matches all.
        maxfeatures : int
            Maximum number of features to be returned.
        method : string
            Qualified name of the HTTP DCP method to use.
        srsname: string
            EPSG code to request the data in
        outputFormat: string (optional)
            Requested response format of the request.
        startindex: int (optional)
            Start position to return feature set (paging in combination with maxfeatures)


        There are 3 different modes of use

        1) typename and bbox (simple spatial query)
        2) typename and filter (more expressive)
        3) featureid (direct access to known features)
        """
        try:
            base_url = next(
                (
                    m.get("url")
                    for m in self.getOperationByName("GetFeature").methods
                    if m.get("type").lower() == method.lower()
                )
            )
        except StopIteration:
            base_url = self.url
        request = {"service": "WFS", "version": self.version, "request": "GetFeature"}

        # check featureid
        if featureid:
            request["featureid"] = ",".join(featureid)
        elif bbox and typename:
            request["bbox"] = ",".join([repr(x) for x in bbox])
        elif filter and typename:
            request["filter"] = str(filter)

        if srsname:
            request["srsname"] = str(srsname)

        assert len(typename) > 0
        request["typename"] = ",".join(typename)

        if propertyname is not None:
            if not isinstance(propertyname, list):
                propertyname = [propertyname]
            request["propertyname"] = ",".join(propertyname)

        if featureversion:
            request["featureversion"] = str(featureversion)
        if maxfeatures:
            request["maxfeatures"] = str(maxfeatures)
        if startindex:
            request["startindex"] = str(startindex)

        if outputFormat is not None:
            request["outputFormat"] = outputFormat

        data = urlencode(request)
        log.debug("Making request: %s?%s" % (base_url, data))
        u = openURL(base_url, data, method, timeout=self.timeout,
                    headers=self.headers, auth=self.auth)

        # check for service exceptions, rewrap, and return
        # We're going to assume that anything with a content-length > 32k
        # is data. We'll check anything smaller.

        if "Content-Length" in u.info():
            length = int(u.info()["Content-Length"])
            have_read = False
        else:
            data = u.read()
            have_read = True
            length = len(data)

        if length < 32000:
            if not have_read:
                data = u.read()

            try:
                tree = etree.fromstring(data)
            except BaseException:
                # Not XML
                return BytesIO(data)
            else:
                if tree.tag == "{%s}ServiceExceptionReport" % OGC_NAMESPACE:
                    se = tree.find(nspath("ServiceException", OGC_NAMESPACE))
                    raise ServiceException(str(se.text).strip())
                return BytesIO(data)
        else:
            if have_read:
                return BytesIO(data)
            return u

    def getOperationByName(self, name):
        """Return a named content item."""
        for item in self.operations:
            if item.name == name:
                return item
        raise KeyError("No operation named %s" % name)

    def get_schema(self, typename):
        """
        Get layer schema compatible with :class:`fiona` schema object
        """

        return get_schema(self.url, typename, self.version, auth=self.auth)


class ServiceIdentification(object):
    """ Implements IServiceIdentificationMetadata """

    def __init__(self, infoset, version):
        self._root = infoset
        self.type = testXMLValue(self._root.find(nspath("Name")))
        self.version = version
        self.title = testXMLValue(self._root.find(nspath("Title")))
        self.abstract = testXMLValue(self._root.find(nspath("Abstract")))
        self.keywords = [f.text for f in self._root.findall(nspath("Keywords"))]
        self.fees = testXMLValue(self._root.find(nspath("Fees")))
        self.accessconstraints = testXMLValue(
            self._root.find(nspath("AccessConstraints"))
        )


class ServiceProvider(object):
    """ Implements IServiceProviderMetatdata """

    def __init__(self, infoset):
        self._root = infoset
        self.name = testXMLValue(self._root.find(nspath("Name")))
        self.url = testXMLValue(self._root.find(nspath("OnlineResource")))
        self.keywords = extract_xml_list(self._root.find(nspath("Keywords")))


class ContentMetadata(AbstractContentMetadata):
    """Abstraction for WFS metadata.

    Implements IMetadata.
    """

    def __init__(
        self, elem, parent, parse_remote_metadata=False, timeout=30, auth=None
    ):
        """."""
        super(ContentMetadata, self).__init__(auth)
        self.id = testXMLValue(elem.find(nspath("Name")))
        self.title = testXMLValue(elem.find(nspath("Title")))
        self.abstract = testXMLValue(elem.find(nspath("Abstract")))
        self.keywords = [f.text for f in elem.findall(nspath("Keywords"))]

        # bboxes
        self.boundingBox = None
        b = elem.find(nspath("LatLongBoundingBox"))
        srs = elem.find(nspath("SRS"))

        if b is not None:
            self.boundingBox = (
                float(b.attrib["minx"]),
                float(b.attrib["miny"]),
                float(b.attrib["maxx"]),
                float(b.attrib["maxy"]),
                Crs(srs.text),
            )

        # transform wgs84 bbox from given default bboxt
        self.boundingBoxWGS84 = None

        if has_pyproj and b is not None and srs is not None:
            wgs84 = pyproj.CRS.from_epsg(4326)
            try:
                src_srs = pyproj.CRS.from_string(srs.text)
                transformer = pyproj.Transformer.from_crs(src_srs, wgs84, always_xy=True)
                mincorner = transformer.transform(b.attrib["minx"], b.attrib["miny"])
                maxcorner = transformer.transform(b.attrib["maxx"], b.attrib["maxy"])

                self.boundingBoxWGS84 = (
                    mincorner[0],
                    mincorner[1],
                    maxcorner[0],
                    maxcorner[1],
                )
            except RuntimeError:
                pass
        # crs options
        self.crsOptions = [Crs(srs.text) for srs in elem.findall(nspath("SRS"))]

        # verbs
        ops = itertools.chain(
            parent.findall(nspath("Operations/*")), elem.findall(nspath("Operations/*"))
        )
        self.verbOptions = list({op.tag for op in ops})

        # others not used but needed for iContentMetadata harmonisation
        self.styles = None
        self.timepositions = None
        self.defaulttimeposition = None

        # MetadataURLs
        self.metadataUrls = []
        for m in elem.findall(nspath("MetadataURL")):
            metadataUrl = {
                "type": testXMLValue(m.attrib["type"], attrib=True),
                "format": testXMLValue(m.attrib["format"], attrib=True),
                "url": testXMLValue(m),
            }
            self.metadataUrls.append(metadataUrl)

    def parse_remote_metadata(self, timeout=30):
        """Parse remote metadata for MetadataURL of format 'XML' and add it as metadataUrl['metadata']"""
        for metadataUrl in self.metadataUrls:
            if (
                metadataUrl["url"] is not None and metadataUrl["format"].lower() == "xml"
            ):
                try:
                    content = openURL(
                        metadataUrl["url"], timeout=timeout, headers=self.headers, auth=self.auth
                    )
                    doc = etree.fromstring(content.read())
                    if metadataUrl["type"] == "FGDC":
                        mdelem = doc.find(".//metadata")
                        if mdelem is not None:
                            metadataUrl["metadata"] = Metadata(mdelem)
                        else:
                            metadataUrl["metadata"] = None
                    elif metadataUrl["type"] == "TC211":
                        mdelem = doc.find(
                            ".//" + util.nspath_eval("gmd:MD_Metadata", n.get_namespaces(["gmd"]))
                        ) or doc.find(
                            ".//" + util.nspath_eval("gmi:MI_Metadata", n.get_namespaces(["gmi"]))
                        )
                        if mdelem is not None:
                            metadataUrl["metadata"] = MD_Metadata(mdelem)
                        else:
                            metadataUrl["metadata"] = None
                except Exception:
                    metadataUrl["metadata"] = None


class OperationMetadata:
    """Abstraction for WFS metadata.

    Implements IMetadata.
    """

    def __init__(self, elem):
        """."""
        self.name = xmltag_split(elem.tag)
        # formatOptions
        self.formatOptions = [f.tag for f in elem.findall(nspath("ResultFormat/*"))]
        self.methods = []
        for verb in elem.findall(nspath("DCPType/HTTP/*")):
            url = verb.attrib["onlineResource"]
            self.methods.append({"type": xmltag_split(verb.tag), "url": url})
